Your Body Wasn’t Built To Last: A Lesson From Human Mortality Rates (2012)

http://singularityhub.com/2012/01/09/your-body-wasn%E2%80%99t-built-to-last-a-lesson-from-human-mortality-rates/

by breck • 11 years ago

102 151 11 years ago

singularityhub.com

icebraining• 11 years ago

"Ignoring, of course, the upward shift in the lifetime distribution that will result from future medical advances."

zkhalique• 11 years ago

Thank you. Yes, that makes a lot of assumptions.

Let's also not forget future dietary advances.

hughes• 11 years ago

Have we made even a single advancement that can increase the age to which humans are capable of living?

We've made lots of progress on stuff that kills us early, but I can't think of anything that makes our bodies actually last longer.

Retra2• 11 years ago

The distinction you are making is a bit artificial.

pavel_lishin3• 11 years ago

Artificial hearts is the most obvious example.

Nagyman• 11 years ago

You mean advancements as in in practice on humans? There certainly seems to be research and progress in areas that affect lifespans (neurdegeneration).

https://en.wikipedia.org/wiki/Calico_(company)

tired_man4• 11 years ago

You can have all the organ replacement you want. Once your drive train (feet/ankles/knees/hips, which ultimately impact on your spine) is shot, all you're gonna want to do is lie in bed.

crusso• 11 years ago

That doesn't make sense unless you have knowledge of what our specific maximum age should be.

"Last longer" is a fairly equivalent way of saying "wasn't killed early".

reasonattlm2• 11 years ago

http://dx.doi.org/10.1186/1478-7954-8-18

Background

The ongoing increase in life expectancy in developed countries is associated with changes in the shape of the survival curve. These changes can be characterized by two main, distinct components: (i) the decline in premature mortality, i.e., the concentration of deaths around some high value of the mean age at death, also termed rectangularization of the survival curve; and (ii) the increase of this mean age at death, i.e., longevity, which directly reflects the reduction of mortality at advanced ages. Several recent observations suggest that both mechanisms are simultaneously taking place.

Methods

We propose a set of indicators aiming to quantify, disentangle, and compare the respective contribution of rectangularization and longevity increase to the secular increase of life expectancy. These indicators, based on a nonparametric approach, are easy to implement.

Results

We illustrate the method with the evolution of the Swiss mortality data between 1876 and 2006. Using our approach, we are able to say that the increase in longevity and rectangularization explain each about 50% of the secular increase of life expectancy.

clamprecht• 11 years ago

But if you multiply that 0.000001% by 7 billion people, what do you get?

mikeash• 11 years ago

The wording of "no human" implies that the total population is already accounted for.

richmarr• 11 years ago

I agree, the article's assumptions are lined up to stretch to an attention grabbing headline, but...

"99.999999% certainty that no human will ever live to the age of 130" is not the same as "99.999999% chance of an individual reaching 130".

Sorry, just my statistics pedantry for the day.

isp• 11 years ago

It's definitely not the same: I think you're missing a "not" in "99.999999% chance of an individual reaching 130". :-)

hueving• 11 years ago

You're mixing up confidence vs probability.

schoen2• 11 years ago

It's not phrased as a "probability that an individual human will live to 130", but as a "probability that any human will live to 130" (although I'm not sure whether that's the calculation that the original author intended to do or whether it was correct).

... but I think it was (if you assume the unlimited validity of that law as ages increase, and its validity to everyone in the population), because I tried to use that formula and my bc crashed (!), the first time I've ever seen that. It was trying to compute e to the power of

-1196855871164164755229127183619028619603176.29243358214210581124

which was the probability of a particular individual surviving to 130 according to the formula. That is a super-small number, which dwarfs the human population of 7 billion, so probably the original author did mean to say the thing about anyone-ever, and was probably correct within these assumptions about exponentials and their applicability.

chiph• 11 years ago

So someone like Lazarus Long has a (very small) chance to exist.

https://en.wikipedia.org/wiki/Lazarus_Long

maaku2• 11 years ago

Also ignoring animals that do have indefinite natural lifespans...

pixl972• 11 years ago

Eh, might as well compare apples and oranges and expect it to describe a banana.

Most animals that live well over 100 years have a very low metabolism. For example turtles and tortoises. Other living organisms that have biological immortality are generally simple creatures. As in all the components of the creature can be replaced and the creature doesn't change in function. Fish, for example can live hundreds of years, but their biology is considerably different than a mammals. That said, whales and alligators can have extremely long lives. It may be that water acts as sunblock and reduces the amount of UV damage allowing life to continue much longer than most land animals.

maaku2• 11 years ago

Right, but it puts a lie to many of the theories that involve mortality being an inevitable result of biological chemistry -- e.g. that cells can only divide so many times before they MUST die.

The reality is that for just about every aging related failure mode, there is an example of some animal somewhere that is able to fix or otherwise defend against that very form of damage, a proof by example that such damage is not inevitable or irreversible.

murbard22• 11 years ago

That title is literally the dumbest sentence in the entire article, which is an outlier in an otherwise interesting piece.

sctb• 11 years ago

We reverted the submission title from “99.999999% certainty that no human will ever live to the age of 130” to the article's.

thomasfoster963• 11 years ago

In other words, John Citizen statistically won't live to age 130. Someone who is better off health wise and is less of a risk taker than the average American - I bet given a lifetime of modern day medicine or better, you've got a great shot at 130.

pixl972• 11 years ago

The key is 'or better'. And no, even with the best modern (as in today) medicine you have no chance of 130. The convergence of accruing damage along with DNA that is not optimized for such long life puts a lot of pressure on the older body. It is very likely that the solution to the age 'problem' will occur at a much younger age with genetic manipulation to avoid or prolong the issues that occur at old age. The question then becomes, if you manipulate your DNA, are you human, or a human subspecies?

JoshTriplett9• 11 years ago

The question then becomes, if you manipulate your DNA, are you human, or a human subspecies?

That doesn't seem like a particularly interesting question. It wouldn't change the conclusion that humans can't naturally live past 120. And that conclusion itself becomes unimportant if we can reliably work around it.

thomasfoster963• 11 years ago

even with the best modern (as in today) medicine you have no chance of 130.

We don't know that. Nobody has lived an entire life with modern medicine. So many things such as organ transplants, vaccines, antibiotics, discouragement of smoking, awareness of carcinogens, etc, have been developed since many of the people aged 100 or above were born, or in many cases, were middle aged.

The question then becomes, if you manipulate your DNA, are you human, or a human subspecies?

That's mostly irrelevant - there is plenty of longevity-related DNA variance within Homo sapiens as it is.

colin_mccabe3• 11 years ago

I'm sorry, but that conclusion is not supported by the article (or by other data). No human being has a "great shot at 130" no matter how modern the medical care is. The longest documented human lifespan is 122 years. Living past 110 years puts you in a VERY exclusive list: https://en.wikipedia.org/wiki/List_of_oldest_living_people Why this is true is one of the great medical mysteries of our times, which we haven't solved yet.

thomasfoster963• 11 years ago

It's true that the oldest verified person lived to 122 years - many of those years lived before antibiotics, before smoking was widely known to be unhealthy, before organ transplants, before widespread use of vaccines. The people on the lists of 'oldest living people' grew up in a significantly tougher world and thus many of their peers probably died young from entirely preventable or curable diseases.

If those people had lived with today's medical technology and knowledge available to them for their whole lives, that list of people living to 110 would be much longer and undoubtedly you'd see an increase in the number of people giving to 120 and probably to 130.

quinndupont3• 11 years ago

Ahh, yes, the fallacy of using history to predict the future, with math. This is a fun kind of math problem, but it completely ignores a huge wildcard, namely, human ingenuity and technology. These kinds of predictions have been toppled many times before simply because they aren't about reality (biological or physical properties), rather they are just calculations about ethereal things. Sometimes mathematics maps on to the physical world in startling good ways (the "unreasonable effectiveness of mathematics"), but biology isn't physics, and human life span is as much social and technological as it is biological. Of course, history is probably our best tool to make such estimations (we don't have any better guides)... until it isn't (that day some new wonder drug is invented, or some new artificial body, etc)

andrewstuart2• 11 years ago

The fallacy of using history to predict the future, with math.

You say that as if we have anything aside from the past that we can use to make predictions.

cookingrobot• 11 years ago

You can look at the mechanics of the thing you're studying and make predictions based on what's possible.

Like if you were watching the development of the space program you could make a prediction about when we'd get to the moon, without just looking at the historical top speed of airplanes we'd built before.

quinndupont3• 11 years ago

Yeah, we don't really (other than, perhaps, physical experiments as cookingrobot's reply suggests). I think such investigations are fun, but also presuppose a very misguided concept of the human and sociality.

51Cards• 11 years ago

This article is just a math lesson on exponential decay using human mortality trends as an example. The author states the following in the article:

Exponential decay is sharp, but an exponential within an exponential is so sharp that I can say with 99.999999% certainty that no human will ever live to the age of 130. (Ignoring, of course, the upward shift in the lifetime distribution that will result from future medical advances)

quinndupont3• 11 years ago

I'm pretty sure the author is referring to the shift in distribution (the movement of the curve), not that medical advances will one day make us able to live past 130 (otherwise the whole point is moot).

digikata• 11 years ago

i.e. don't confuse a statistical characterization of the data with more fundamental physical processes from which the statistics arise. Though that said, is there a scientific way to categorize the difference between models for one vs another without a human looking at the situation and trying to decide?

epistasis• 11 years ago

but biology isn't physics, and human life span is as much social and technological as it is biological.

The only way this statement has basis in fact is if you're talking about lifespans that are less than 80-100 years. Clearly there are large technological and social influences on early termination of life.

But there's pretty much no basis for asserting technological influence on the other end of the spectrum.

jessaustin• 11 years ago

A growing number of Americans are living to age 100. Nationwide, the centenarian population has grown 65.8 percent over the past three decades, from 32,194 people who were age 100 or older in 1980 to 53,364 centenarians in 2010, according to new Census Bureau data. In contrast, the total population has increased 36.3 percent over the same time period. [0]

If this hasn't been the result of social and technological factors, what has caused it?

[0] http://money.usnews.com/money/retirement/articles/2013/01/07...

jpstory• 11 years ago

"So...you're saying theres a chance!"

powertower2• 11 years ago

I'm 99.999999% certain I would not want to live that long.

EC1• 11 years ago

Really? All I can think about is how to not die. The thought terrifies me. It got to a point where it's my main motivator in what I do. I used to be lazy and play video games all day and when I realized how finite and easy destructible our lives are, I get crazy scared and work like crazy so I don't waste my time. There's so much I want to learn and do. The only problem is the limit of time.

Death is incredibly terrifying. I don't understand it and I don't want to, I just want to live. Forever preferably.

noir_lord2• 11 years ago

It's strange how different people's attitude to death are, I don't fear it at all, I'm going to enjoy life for as long as I can then check out in the least painful way possible.

Maybe it comes from been atheist (I'd find proof of life after death a lot more scary), the universe was around 14 odd billion years before I was and it'll be around long after I'm gone.

PakG17• 11 years ago

I would be quite interested in understanding why people find death terrifying. I'm likely in a minority, but I look forward to death. That doesn't mean I'm suicidal. It means that I view death as an important moment in my life, one that will force me to measure whether I'm satisfied with the way I lived my life. I'll no doubt have regrets, but I'll have smiles too. I could say that being a person of faith may influence my looking forward to death, but I imagine that even if I wasn't a person of faith, I'd still have a similar mindset. I am very curious why people would want to live forever on this earth. It seems like it'd become quite dreary and boring, especially if I gradually lose control over all my normal physical and mental functions.

kanzure• 11 years ago

Death is incredibly terrifying. I don't understand it and I don't want to, I just want to live.

    Do not go gentle into that good night, 
    Old age should burn and rage at close of day; 
    Rage, rage against the dying of the light.
    Though wise men at their end know dark is right, 
    Because their words had forked no lightning they 
    Do not go gentle into that good night.

    Good men, the last wave by, crying how bright 
    Their frail deeds might have danced in a green bay, 
    Rage, rage against the dying of the light.

    Wild men who caught and sang the sun in flight, 
    And learn, too late, they grieved it on its way, 
    Do not go gentle into that good night.

    Grave men, near death, who see with blinding sight 
    Blind eyes could blaze like meteors and be gay, 
    Rage, rage against the dying of the light.

    And you, my father, there on the sad height, 
    Curse, bless me now with your fierce tears, I pray. 
    Do not go gentle into that good night. 
    Rage, rage against the dying of the light.

edit: Oh I guess something more practical than reciting poetry might be useful, so uh, (1) read every paper ever published, (2) acquire all possible engineering and lab skillz, (3) raise lots of capital, and (4) remember to have fun.

Quanticles• 11 years ago

Even if you had the same body as when you were 25?

espadrine• 11 years ago

I can already feel my brain slowly doing some kind of overfitting (in neural network terms), and that already bothers me without me being able to avoid it.

I can absolutely understand someone that says they would rather have a healthy <130 years life.

semicolondev• 11 years ago

"Most people die at 25 and aren't buried until they're 75."

- Benjamin Franklin

Retra2• 11 years ago

It always seems absurd to me that there are people walking around who literally want to die. It really highlights how closely people associate suffering with aging. It seems especially short-sighted when everything we want to do to extend life would involve reducing that suffering as well.

I.e, you won't live a long life if you aren't healthy. So you are basically asking for an unhealthy life.

matheweis• 11 years ago

All religious aspects aside, it's amazing that this was documented back to at least 2nd century BCE to within 2.5 years or so.

"... they are mortal; their days will be a hundred and twenty years." https://www.biblegateway.com/verse/en/Genesis%206%3A3

... with the longest living person in modern times documented as being 122 yrs, 164 days: https://en.wikipedia.org/wiki/Jeanne_Calment

javajosh• 11 years ago

Does living 2 years and 164 days over the deadline (so to speak) count as a sin?

krapp• 11 years ago

Knowing the Old Testament, probably. You live until God kills you, but it's still a sin to live too long.

Nadya• 11 years ago

The Bible isn't a good prediction of age.

  Seth lives to be 912 years of age.  (Gensis 5:8 ) 
  Enosh lived to be 905 years of age. (Gensis 5:11) 
  Reu had a son at 32 then lived another 207 years living to be 239 years of age. (Gensis 11:20-21) 
  Abraham lived to be 175 years of age (Gensis 25:7)

Also the passage you noted, Gensis 6:3, is often seen as referring to the amount of time from when God determined to destroy mankind to when God sent a global flood and not the lifetime of humans mandated by God.

pugio• 11 years ago

Actually, the Jewish tradition is that Moses lived 120 years, and that, after him, 120 years was the approximate cap on human life. Many Jewish well-wishings end with something like "may you live until one hundred and twenty".

nicholas73• 11 years ago

In middle school (Christian) our religious studies teacher told us that ancient Jews used "40 years" as an expression of a generally very long time period. So 120 years might be an extension of it, not an actual prediction.

I did always find it interesting that it happens to be about right though. But of course it's easy to just record who lived to be the oldest.

gwern• 11 years ago

If you look through religious texts and physicians' claims, you can find almost any date. In Stambler's _A History of Life-Extensionism: In The Twentieth Century_ http://www.longevityhistory.com/book/indexb.html (which actually covers more than the title indicates), you can find estimates of maximal lifespan of baseline humans ranging from 110 to 300+; someone was going to be close to right.

alejohausner9• 11 years ago

The article addresses Gompertz' law: the probability of dying in any given year increases exponentially with age (older people have ever higher death rates). This is an EMPIRICAL FACT. As you live longer, this probability accumulates exponentially, so the probability of being alive falls super-exponentially: p(being alive) = aexp(-exp(bt)).

I'm pretty sure there ain't nothing you can do about this. Why not? Because evolution built it pretty strongly into our genes. Here's how I see it: if an organism arose which had this "death gene" turned off, it would not adapt to sudden changes in the environment. It might be susceptible to a novel infectious agent which wipes out the whole species. Thus evolution tends to weed out immortal or very long-lived organisms.

Don't forget how natural selection works. It's not single creatures that adapt; it's about whole species. The only way for a species to adapt is for some of its individuals to die and be replaced by their offspring which differ genetically from their parents.

Evolution needs death to work. Hence death is built-in.

Look at this scary graph (with a logarithmic y axis!):

https://en.wikipedia.org/wiki/Gompertz%E2%80%93Makeham_law_o...

and then tell me that medical advances will do anything to make you live to 200. Go on, I dare ya.

alejohausner9• 11 years ago

This also gets me thinking about pesticides in apples, of all things. I read Michael Pollan's "The Botany of Desire" a while ago, and was really struck by the story of Johnny Appleseed. For those of you who didn't grow up in the USA, he travelled through the country planting apple seeds, so that later settlers would find whole apple orchards in place when they moved in.

The interesting thing is that apples don't "spring true" from seed. In other words, an tree that bears sweet apples will almost certainly have seeds that lack the gene for sweetness. Apple trees grown from seed will certainly bear crab apples. They are sour, and are only good for fermenting and making alcoholic apple cider. Settlers were certainly happy to have crab apples, because cider is fun and easy to make. But they certainly didn't eat those apples.

If you want sweet apples, you have to use grafting: if you are lucky enough to get a tree with sweet apples, you will probably immortalize it, but taking cuttings from its branches, and grafting them onto ordinary crab-apple root stock. The part of the tree above ground will be genetically different from the part below. If the root stock nears death, you'll take cuttings from the part above ground and graft them onto new roots.

This is all very nice, but it sidesteps evolution: you've created an immortal organism, which won't be able to fight off insects, fungus, and bacteria that attack apples, and which are constantly evolving to overcome a plant's defenses. Since the tree can't generate new chemicals that kill or repel these attackers, humans have to invent fungicides and insecticides to do it for them. That's why apple farming relies so heavily on spraying scary chemicals on the trees.

Any war you declare on time and change is a war you will lose.

dorgo2• 11 years ago

My theory about evolution and aging is that evolution just doesnt care about individuals after they created offspring. There is no advantage for an individual (or a species) to live longer than to create offspring. Hence evolution never cared to optimize us for a longer life.

GFK_of_xmaspast• 11 years ago

Didn't your grandparents ever baby-sit you.

secabeen• 11 years ago

There's something to that, but it doesn't explain menopause in women. If reproduction is the end-all-be-all, why not evolve the ability to reproduce throughout the natural lifespan. See the Grandmother Hypothesis for a possible explanation: https://en.wikipedia.org/wiki/Grandmother_hypothesis

Symmetry6• 11 years ago

I'm not sure that makes any sense. If there are sudden changes in the environment then the less fit animals will die off without any need for a death gene. If there aren't any changes in the environment then there's no need for animals to die off. Evolution works just fine with prokaryotes which don't really get old in the sense that we do.

Also technology allows us to do many things that aren't allowed for by our evolution, like flying to the Moon. Evolution isn't an all-powerful force but something that works strictly through variation and selection. If we find the physical process that cause aging and how to stop them then there's nothing evolution can do to stop us.

alejohausner9• 11 years ago

Granted, sudden changes to the environment would kill off the less fit individuals. So I'll change my argument a bit:

Suppose you've overcome infant mortality, and have also solved the problem of adult mortality, so all subsequent people are immortal. Suppose moreover that young adults insist on having more than zero children (that's likely to continue, you'll agree). Now you've got a population that won't stop growing. Resources are finite, and there will be mass starvation.

What are your options in such a scenario? Should you kill off old people, kill off young people, or prevent all future babies?

Suppose you prevent all future babies. Then you end up with no more sex, no more genetic variability, and now the whole species might be susceptible to a sudden environmental change.

So my argument is that old people must die to make room for genetically-different young people. Without natural death, there will be less room for evolutionary adaptation.

darkmighty4• 11 years ago

The issue is rate of environment change. If your individuals have 100-year lifetimes and changes occur at 1-year rate, then clearly there's a problem. Even if those 100-year individuals reproduce throughout their lives, the older individuals won't bear modifications. So if the environment can change quickly, it's plausible there's a mechanism to secure existential threats to the species by maintaining a short reproductive cycle at the expense of extra overhead to recreate individuals.

logfromblammo2• 11 years ago

Medical advances will make me live to 200 by replacing some of my body's stem cells once every 20 years, followed by additional critical advances during my "borrowed time".

Modeling past behavior is not going to accurately predict future behavior. The model suggests that older people are steadily losing some quantity of a finite resource that acts as a protectant against otherwise fatal conditions. Replenishing that resource would therefore allow some people to move backwards on the age-mortality curve, effectively transforming the super-exponential curve into an exponential curve. That would make your probability of living to 160 years after your treatments begin around 90%, rather than an iota more than 0% (assuming average 1/1500 annual mortality rate).

That gives you a lot more time to find and eliminate the individual risk factors which contribute to various causes of mortality.

Recent research has found very old individuals whose entire red blood supply is likely to be derived from a single hematopoietic stem cell. Other research has demonstrated regular transfusions of whole blood from younger donors into older recipients as improving specific age-related health conditions. (See also [0],[1].)

That old sci-fi trope about people cloning themselves for the spare parts will eventually become reality, except the clones will be harvested at 18 days old from an artificial growth medium instead of after 16 years in a secret island facility. Some nations will ban the practice under political pressure from religions, and it will just move to the black market.

What's really going to close the door on clinical immortality is economics and politics, not medical science.

[0] http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4021776/

[1] http://www.nature.com/nri/journal/v13/n5/full/nri3433.html

reasonattlm2• 11 years ago

Aging is caused by damage accumulation.

There are very good ways to model how that works, see for example reliability theory [1].

There is little difference at this level of modeling between a human and a car. It is just a complex system of redundant components subject to breakage. If you repair it well it enough it has an indefinite mean time to failure.

The important thing to appreciate about medicine is that no present medicine does anything to repair damage. All advances in medicine and related technologies relevant to control over disease that have led to longer lives across the board have only modestly slowed accumulation of damage. Slowing damage accumulation more deliberately or via engineering metabolism is very hard and the best of approaches can't beat the outcomes of exercise or calorie restriction, they aren't moving the needle any further. I don't expect them to, either.

Fortunately, there is the alternative approach of repair, with the outcome of indefinite healthy life spans for sufficiently comprehensive repair.

The future is one in which the root cause damage is periodically repaired. Lines of research related to SENS for example, such as senescent cell clearance. Other than some forms of stem cell replacement, there are no implementations of damage repair today, but that will change very rapidly once things get going.

[1] https://en.wikipedia.org/wiki/Reliability_theory_of_aging_an...

sliverstorm2• 11 years ago

Aging is caused by the accumulation of damage, but damage accumulates because your repair systems stop working as well (for reasons I don't really know). As even just a very simple example, an adult takes longer to heal from cuts, scrapes, bruises and breaks than a young child.

xlm1717• 11 years ago

I wouldn't put a limit on human ingenuity to overcome this problem. Evolution has already become a tool for humanity to further itself. See: Farming. It will only come under greater human control as genetic engineering continues developing.

Maybe one day, we will be able to turn this "death gene" off. What happens then?

If a novel infectious disease pops up, sure it will cause widespread death, but it's highly unlikely it will cause the death of the species. We'll either save a few of us in some deep underground bunker, or we'll figure out how to beat it. That's really the only Earth-based threat that can still threaten the species as a whole.

Evolution operates on a scale of decades and centuries. Human ingenuity operates on much shorter time scales. We don't fall under natural selection anymore. We are the ones who select now. We don't need some of us to die for us to adapt. We can adapt to every single biome and environmental condition on Earth without waiting for genetic variation to produce individuals who can. Evolution may need death to work, but we no longer need evolution for us to work.

jfoutz• 11 years ago

The ebola vaccine was developed ridiculously quickly. Compared to 20 years ago, it's practically magical. Yeah, There is probably something worse than spanish flu in our future. We may not survive, but our odds so much better off now.

I think our most serious earth based threat is us. Nuclear war, engineered diseases, or (imho most likely) destruction of the environment.

summerdown2• 11 years ago

The thing is, technological advances can be exponential, too. Moore's law is one example, but there are others. Here's a quote from Ray Kurzweil, who's a leading exponent of this idea:

"People declared the Human Genome Project a failure halfway through, when one percent had been decoded -- they said it'd take 700 years. My reaction was, no, we're almost done. It was finished seven years later."

Personally, I think Kurzweil is an optimist and I suspect it'll be too late for most of us, but we are just beginning to learn to rewire our genes. Take a look at this link, and notice how many significant events happened in the last fifteen years:

https://en.wikipedia.org/wiki/Gene_therapy#History

Now, imagine that level of change accelerating, because we're still in the early days.

happyscrappy3• 11 years ago

Wow, if you survive birth you don't have that level of risk until your almost sixty? Can that be right?

alejohausner9• 11 years ago

Yep. So, enjoy yourself and ignore death until you reach retirement age. Then, keep looking over your shoulder to see if the grim reaper is catching up on you.

BjoernKW2• 11 years ago

As Steve Jobs eloquently put it in his Stanford commencement speech: "Death is very likely the single best invention of Life. It is Life's change agent."

In my opinion this not just applies to the species as whole but to individuals, too: Old people tend to become set in their ways.

It's not overpopulation but this very issue that's the most evident problem with extreme longevity or immortality: As soon as a significant amount of people will be able to live forever, change and human development will likely cease to exist in the long run. Perhaps this can be delayed by not just rejuvenating the body but at the same time also preventing the biochemical processes that lead to fossilization of thinking but in the end this might be unavoidable and ultimately lead to the extinction of the human race due to sheer boredom.

alejohausner9• 11 years ago

Then again, maybe Jobs' view of death was colored by knowing he had pancreatic cancer. It might have made him more fatalistic.

Also, can it be said that the older Steve was more set in his ways than when he was younger? His example argues against characterizing old people in that way. Mind you, he's just one data point.

sliverstorm2• 11 years ago

Old people tend to become set in their ways

We have opposing problems approaching though. As our fields of knowledge grow ever deeper, our investment in education in each individual grows and their productive years grow fewer.

With a fixed lifespan, there is a fixed amount of education you can invest in a person. That will either limit our development of science, math, etc or it will force us ever further down the road of abstraction piled on top of abstraction.

saurik• 11 years ago

...and yet there are things that last both ludicrously longer than us and things that seem to be theoretically capable of lasting forever but in practice fail anyway by eventually screwing up and either damaging itself beyond repair or getting dismantled by another organism. It is not clear that planned obsolescence is a necessary trait everything must have to achieve market domination, even when considering a defensive strategy for a potential disruptive competitor.

AndrewKemendo• 11 years ago

The unstated assumption here is that the evolutionary process is good for humanity in the long run.

I would argue that is not the case, as in the long run there will be some event that puts humanity at existential risk.

Better then to self direct our own evolution to something that is more robust.

I find these discussions funny because so many of the tech crowd are big advocates of terraforming mars or some other such "insurance" for humanity's survival - yet very few say, instead of keeping the fragile human as the future model, lets change the model and transform what was human biology into something more durable. That's not to say we have the answer as to how to do that, but it's at least a better eon level goal.

scythe• 11 years ago

I'm pretty sure there ain't nothing you can do about this. Why not? Because evolution built it pretty strongly into our genes. Here's how I see it: if an organism arose which had this "death gene" turned off, it would not adapt to sudden changes in the environment. It might be susceptible to a novel infectious agent which wipes out the whole species. Thus evolution tends to weed out immortal or very long-lived organisms.

Your prediction is right, but you've expressed the conclusion wrong: thus long-lived organisms are unlikely to persist, i.e. removing a single "death gene" only allows you to experience one of the many other forms of death. The species is never at risk because any potential cause of death is always present.

I believe that the current hypothesis is essentially that evolution does not need you around longer than it takes to produce and raise healthy offspring, and furthermore, it does not need you to reproduce beyond prime years when your offspring are likely to be healthiest. So genes having these effects are not selected for; furthermore because most genes have side-effects (e.g. sickle-cell anemia), they are likely selected against.

Look at this scary graph (with a logarithmic y axis!):
https://en.wikipedia.org/wiki/Gompertz%E2%80%93Makeham_law_o....
and then tell me that medical advances will do anything to make you live to 200

I wouldn't be surprised if we reach 150. "Medical advances" is a broadly-defined category. Indefinite extension is rather unlikely in the foreseeable future, though.

alejohausner9• 11 years ago

removing a single "death gene" only allows you to experience one of the many other forms of death

I see your point. On the other hand, why are there so many ways to die when you grow old? If one form of death doesn't get you, whey are there so many built-in mechanisms for death, in each of us? Why does your body betray you without fail, eventually?

Why do mayflies die so young, just after they reproduce? Perhaps evolution has no need of them after they reproduce, but that's not how it looks like to me, in the case of mayflies. It is one thing to say that there is no advantage to living after reproduction, and another to say that you MUST die after reproduction. It is perfectly conceivable to imagine post-reproductive mayflies surviving for many years.

Heck, post-reproductive humans survive again as long after the end of fertility.

Indefinite extension is rather unlikely in the foreseeable future, though

I agree with you there. That was pretty much my point all along. And I was trying to put forth a rational argument for WHY I think that, but I can't come up with a totally convincing explanation.

eevilspock• 11 years ago

I think this Quora answer says what you're saying, arguing that "the human lifespan [is] not a limit but an optimization":http://qr.ae/L5v6z

Animats• 11 years ago

That's much closer to reality. Death is mostly a timeout, not a wearout, and this has evolutionary benefits. Medicine has made great progress on wearout and damage problems, but hasn't yet made much progress on the timeout issues, the ones which degrade the self-repair mechanisms over time.

This will probably be solved eventually, although it may only work for new organisms created from genetically engineered DNA.

Bear in mind how new our understanding of how life works really is. The role of DNA wasn't understood at all until 1953. DNA manipulation is still at the "hack and see what works" level; designing and editing DNA from first principles is not yet here.

Buttons840• 11 years ago

Evolution needs death to work.

Wouldn't it be, "evolution needs birth to work"? Death only helps evolution insomuch as it helps birth. Death often does help birth because old genes aren't hanging around using up all the resources and preventing the birth of new genes.

maratd2• 11 years ago

Evolution needs death to work. Hence death is built-in.

Yes, but life duration is an equation. The main component of that equation is parasite load.

Here's how I see it: if an organism arose which had this "death gene" turned off, it would not adapt to sudden changes in the environment.

It's not about sudden changes. Those almost never happen. It's about the Red Queen.

https://en.wikipedia.org/wiki/Red_Queen_hypothesis

Parasites are constantly shuffling their genes, so we must as well, to resist them.

So going back to our equation ... life duration is directly correlated to parasite load. Tons of viruses/bacteria/etc. trying to kill you, death gene tweaks the lifespan into the low numbers to decrease the duration between variation to adapt to the parasites. Almost no parasites? You live for thousands of years. And there are creatures on this planet that do. They have few/no predators or parasites that ail them.

Want to increase humanity's life span? Kill off all the parasites. Your death gene will adapt over time and increase the lifespan.

ringwalt• 11 years ago

Wouldn't parasites be a constant factor in the death rate? How do you explain an exponentially rising death rate? The "criminals" in the article's example are more like mutations or other damage that builds up in cells, which increase the death rate exponentially as your body's ability to catch them falls linearly over time. If you have bacteria in your bloodstream you're already in septic shock, infections can't explain, say, heart disease or most types of cancer.

Houshalter2• 11 years ago

This is a bullshit "just-so story". In the wild most animals die long before they reach their age limit. There isn't enough selection pressure for evolution to spend resources to prolong life.

Evolution doesn't work on whole species. Or even individuals. It works on genes. If there is a gene that prolongs the life of an animal by 10 years, and it has 1.5x more babies in that time, then that gene will spread itself 1.5x more than the alternative genes. It doesn't matter if it's detrimental to the species in the long run. Lots of genes are.

Sure evolution needs death to work, but that's a very different claim than saying it selects for death.

It's certainly possible to defeat aging. There are a number of animals that don't age at all: https://en.wikipedia.org/wiki/Negligible_senescence

Medical advances could definitely make you live to 200. We are very close to the ability to grow organs, and eventually entire bodies. Even if your body ages, you could just replace it. That would extend your life a ton on it's own. Add new brain tissue over time as the old stuff dies, and rejuvenate it a bunch with young blood (which has been shown to improve old brains a lot.)

Or you could get cryopreserved and wait until the really distant future, when have nanotechnology and gene editing and who knows what.

outofcuriosity2• 11 years ago

I apologize for the disillusionment that will follow:

1) Negligible senescence occurs mostly in organisms radically-different from humans and we have no idea how to edit those pathways into humans or if those pathways actually hold any value to humans. Hydra cells still die but the organism itself doesn't age. If you want to apply a gene-level anti-senescence therapy to an organism, you have to transfect the traits correctly into every cell of the organism--trillions of opportunities for catastrophic failure.

2) Gene editing probably has downstream cascades that we can't foresee.

3) Organ transplants become more risky with age, and the mortality risk from anesthesia does as well. If you were to replace your body, your brain would necessarily be the same age--and since we can't fix the (conjectured) senescence pathways in a living organism, you'd eventually be a senile individual in a young body. There's some neuroregenerative therapies that hold promise, but any "regenerative cell therapy" could also be read as "may create proliferative tumors"

4) Cryopreservation of a living organism is assumed to kill it, or at least alter it radically enough that its original functions will never be restored. Reconstructive nanotechnology is probably impossible due to heat dissipation and brownian motion--you'd have to hope that somehow a human scientist figures out how to engineer a new class of cell that is capable of navigating and repairing all extant human cells, which is more-or-less Clarke's Law.

We are not here forever. Oxygen metabolism literally rusts our bodies over time, disrupting and destroying countless pathways. Aging and death was part of the mitochondrial bargain. Tortoises have been evolving against the bargain's drawbacks for longer than humans have been around, and they still aren't immortal.

rue• 11 years ago

Thus evolution tends to weed out immortal or very long-lived organisms. […] Evolution needs death to work. Hence death is built-in.

The description of a process in the past that we refer to as evolution could be argued to have benefited from death.

Mutation happens anyway. Offspring happens anyway. It does not require death. You could say that death is good because it frees resources for the younger generations—but there is a hidden assumption there: that at some point, there has been some preceding form that did have a vastly longer lifespan and it was less viable because of that.

In reality, we have evolved from very, very short-lived organisms, and the trend has been upwards as benefits of those long-surviving members (wisdom, experience, etc. beyond merely bearing offspring) have given an advantage to the survival of species.

…

However, none of that is actually necessary for the evolution of a species in the sense of a mechanism that reacts or proacts to environmental changes—it can just as well be artificial.

colin_mccabe3• 11 years ago

I think you are misunderstanding how natural selection works. You seem to be implying that there is some guiding hand behind the evolution of each species. In fact, if longer life were an advantage for an individual member of any species, the gene pool would gradually shift towards longer life. Some species do indeed have extremely long lives-- some trees live for thousands of years, and some whales and turtles can live and even reproduce for more than a hundred years.

Instead, life length is a tradeoff that is made at the individual level. A longer life means more opportunities to reproduce (or help your offspring), but it also means that you have to set a higher limit for the number of divisions each cell can make, which can decrease cancer resistance. A slower metabolism will produce fewer harmful byproducts, but give you less energy than a fast-burning metabolism. And so on.

Longer life makes more sense for more intelligent organisms, since they can be more effective when they're older due to what they have learned. Often, they need teach the young, which can have relatively long gestation times. But an organism's lifespan is always going to be oriented around its reproductive cycle.

With all that being said, humans are very clever and I wouldn't be surprised if ways were found around human mortality eventually. I can't help thinking of all the "humans were never meant to fly" arguments that people used to pooh-pooh heavier than air flight in the old days. There's no fundamental reason why life extension couldn't be done except time and effort. But I am not as optimistic as Kurzweil about the timeframe (who is?)

bane• 11 years ago

You know, I'm okay with this body not lasting. I'm not too terribly fond of it anyway.

I just want a good and working migration plan.

tim333• 11 years ago

Yeah, I second that. In most religious belief your soul or some part of you lives on. And some people think you can contact them with seances and that the spirits can influence what happens here. I don't see why we can't build an electronic version of that in the future.

Symmetry6• 11 years ago

In terms of mechanisms for aging I think Nick Lane has some pretty good arguments that it mostly has to do with evolution in your body's population of mitochondria. The evidence with the unexpectedly long lives of hummingbirds is at least suggestive.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1483179/

norea-armozel• 11 years ago

For me, death is just another fact of life but I don't think dying from old age will be one of those facts that will be around for much longer (in terms of a century). Yet diseases, accidents, and murder will still be there to cut life short to be sure.

I just think it's odd that there's a great many essays on the matter of death where people argue it's preferable to accept it than to fight it even if it's futile. I'd rather go out with a bang than a whimper. At least then I know I tried and I didn't let death off too easy.

douche• 11 years ago

I don't remember where I originally picked this up, but I recall reading that generally, for warm-blooded mammals, there is a pretty strong correlation between resting heart rate and lifespan. Except that humans are a huge outlier.

Ah, here's the graph, possibly not from the most reputable source, but it's what the googles found me first http://www.runnersworld.com/sweat-science/how-many-heart-bea...

I do sometimes wonder if the delaying of child-rearing has some effect on lifespan. Historically, it's not uncommon to find mothers and fathers in their mid teens, and adulthood was commonly understood to start at something like 16 or 18. In western countries, we're deferring child-rearing into the late twenties, early thirties, and full adulthood keeps creeping upwards as well.

dang• 11 years ago

https://news.ycombinator.com/item?id=9414176

Your Body Wasn’t Built To Last: A Lesson From Human Mortality Rates (2012)

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